BIOLOGY 109 MIDTERM EXAM
QUESTIONS AND ANSWERS
DNA - ANSWER--Antiparallel double helix
-composed of a strand of nucleotides: 5 Carbon monosaccharide, phosphate groups,
and nitrogenous bases
-Backbone: phosphodiester bond (sugar-phophate)
Direction: 5'----->3'
Semiconservative (DNA) Replication - ANSWER-each new double helix contains
one original strand and one new strand
Leading strand - ANSWER-Strand of DNA thats replicated continuously 5'-3'
easy to replicate
DNA polymerase follows the helicase as it opens up the double helix
Lagging strand - ANSWER-Polymerase must synthesize Okazaki fragments.
Okazaki fragments are put together by DNA ligase
Helicase - ANSWER-Enzyme that unwinds the double helix for replication to start
DNA polymerase - ANSWER-Enzyme that synthesizes DNA
DNA Ligase - ANSWER-Enzyme that joins Okazaki fragments together on lagging
strand
DNA Gyrase - ANSWER-Enzyme that relieves supercoiling of DNA; relieves stress
DNA Primase - ANSWER-Enzyme that makes RNA primers to start the synthesis of
a strand of DNA
Excision - ANSWER-repair of incorrectly copied DNA bases
Kinetochore - ANSWER-DNA strand synthesized in one place
Telomerase - ANSWER-Enzyme that adds nucleotides to the end of a chromosome
by copying RNA template
Prokaryotic Replication - ANSWER--Double helix is unwound by helicase
- creates replication bubbles and forks
-DNA polymerase 3 adds nucleotides to 3' end of daughter strand of DNA
-semi discontinuous
Replisome - ANSWER-Consists of primes and helices and
2 DNA polymerase molecules
Eukaryotic Replication - ANSWER--Replicated from multiple origins of replications
-more complex
, -Lacks a primer to synthesize to the end
-everytime it replicates, it gets shorter and shorter
-Telomeres
Central Dogma of Molecular Biology - ANSWER-DNA---->RNA-----> Protein
Transcription - ANSWER-Flow of info from DNA--->RNA
Prokaryotic Transcription - ANSWER-Contains a single type of RNA polymerase
found in 2 forms
Core polymerase - ANSWER-PROKARYOTIC TRANSCRIPTION
capable of RNA elongation, but not initiation
Holoenzyme - ANSWER-PROKARYOTIC TRANSCRIPTION
composed of both the core enzyme and sigma factor which is required for
transcription initiation
The Miller- Urey Experiment - ANSWER-molecules can spontaneously form from
simple chemicals
Carbohydrates - ANSWER--Monosaccharides
-Makes glycosidic bonds
-Makes disaccharides by dehydration synthesis
-Forms hexes and pintos rings in (aq)
Nucleic Acids - ANSWER-Consists of nitrogenous base, 5 carbon sugar, and
triphosphate group
Nitrogenous Bases - ANSWER-Adenine (DNA)
Thymine (DNA)
Guanine (DNA)
Cytosine (DNA)
Uracil (RNA, DNA)
Purines - ANSWER-Adenine
Guanine
Pyrimidines - ANSWER-Cytosine
Thymine
Uracil
Proteins - ANSWER--Makes peptide bonds from amino acids
-20 amino acids
-Carboxyl group (NH2)
-enzyme catalyst
Primary structure - ANSWER-just the amino acid sequence
very strong
covalent bonds
QUESTIONS AND ANSWERS
DNA - ANSWER--Antiparallel double helix
-composed of a strand of nucleotides: 5 Carbon monosaccharide, phosphate groups,
and nitrogenous bases
-Backbone: phosphodiester bond (sugar-phophate)
Direction: 5'----->3'
Semiconservative (DNA) Replication - ANSWER-each new double helix contains
one original strand and one new strand
Leading strand - ANSWER-Strand of DNA thats replicated continuously 5'-3'
easy to replicate
DNA polymerase follows the helicase as it opens up the double helix
Lagging strand - ANSWER-Polymerase must synthesize Okazaki fragments.
Okazaki fragments are put together by DNA ligase
Helicase - ANSWER-Enzyme that unwinds the double helix for replication to start
DNA polymerase - ANSWER-Enzyme that synthesizes DNA
DNA Ligase - ANSWER-Enzyme that joins Okazaki fragments together on lagging
strand
DNA Gyrase - ANSWER-Enzyme that relieves supercoiling of DNA; relieves stress
DNA Primase - ANSWER-Enzyme that makes RNA primers to start the synthesis of
a strand of DNA
Excision - ANSWER-repair of incorrectly copied DNA bases
Kinetochore - ANSWER-DNA strand synthesized in one place
Telomerase - ANSWER-Enzyme that adds nucleotides to the end of a chromosome
by copying RNA template
Prokaryotic Replication - ANSWER--Double helix is unwound by helicase
- creates replication bubbles and forks
-DNA polymerase 3 adds nucleotides to 3' end of daughter strand of DNA
-semi discontinuous
Replisome - ANSWER-Consists of primes and helices and
2 DNA polymerase molecules
Eukaryotic Replication - ANSWER--Replicated from multiple origins of replications
-more complex
, -Lacks a primer to synthesize to the end
-everytime it replicates, it gets shorter and shorter
-Telomeres
Central Dogma of Molecular Biology - ANSWER-DNA---->RNA-----> Protein
Transcription - ANSWER-Flow of info from DNA--->RNA
Prokaryotic Transcription - ANSWER-Contains a single type of RNA polymerase
found in 2 forms
Core polymerase - ANSWER-PROKARYOTIC TRANSCRIPTION
capable of RNA elongation, but not initiation
Holoenzyme - ANSWER-PROKARYOTIC TRANSCRIPTION
composed of both the core enzyme and sigma factor which is required for
transcription initiation
The Miller- Urey Experiment - ANSWER-molecules can spontaneously form from
simple chemicals
Carbohydrates - ANSWER--Monosaccharides
-Makes glycosidic bonds
-Makes disaccharides by dehydration synthesis
-Forms hexes and pintos rings in (aq)
Nucleic Acids - ANSWER-Consists of nitrogenous base, 5 carbon sugar, and
triphosphate group
Nitrogenous Bases - ANSWER-Adenine (DNA)
Thymine (DNA)
Guanine (DNA)
Cytosine (DNA)
Uracil (RNA, DNA)
Purines - ANSWER-Adenine
Guanine
Pyrimidines - ANSWER-Cytosine
Thymine
Uracil
Proteins - ANSWER--Makes peptide bonds from amino acids
-20 amino acids
-Carboxyl group (NH2)
-enzyme catalyst
Primary structure - ANSWER-just the amino acid sequence
very strong
covalent bonds
